it is an instant deposit of energy in the atmosphere. and so forth nationally we were able to tell them, we, i mean people, my scientific brethren who study this, were able to tell them no, that s not somebody's first strike it was actually a cosmic event. so that was in the 1990s. and if this had happened over the pas civic, nobody would have noticed. >> is it, in fact happening all the time? this kind of thing. >> yes, so something of this magnitude we might imagine is perhaps once a decade. i mean if one happened in the 90s and one happened now and you fill in for the areas of the earth it would not have been noticed f it did. for example the north pole or antarctica or northern canadwhe hardly anydy lives. you could easily sort of hide one of these from anybody's view simply because of the large swathes of area on earth's surface where nobody inhabits it. so i could imagine it would be once every five to ten years. >> and what exactly is it? what is a meteor and what is an asteroid for that matter? >> yeah, well, we can go back, aste